import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * @author zx
 * @date date 2019-11-17 21:17:28
 */
public class T1 {

//    private static int[] mem = new int[];

    public static int cut(int n){
        if(n == 1){
            return 1;
        }
        if(n == 2){
            return 2;
        }

        int res = -1;
        for (int i = 1; i < n; i++) {
            res = Math.max(res, i * cut(n-i));
        }
        return res;
    }

    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        String read = bufferedReader.readLine();
        int n = Integer.parseInt(read);
        System.out.println(cut(n));
    }
}
